Abstract

Planar-type quantum-dot devices have been fabricated and characterized. Aluminum metal electrodes with interelectrode spacing of 30 nm have been deposited on an InAsself-assembled quantum-dot wafer to form the quantum-dot devices. The current–voltage characteristicsmeasured from the devices, in which a single quantum dot is placed in between the electrodes, exhibit negative differential resistance effects at the temperature above 77 K. They are interpreted as due to three-dimensional–zero-dimensional resonant tunneling through the InAsself-assembledquantum dot.